Impulsivity, Peer Influence, and Adolescent Substance Use
Individuals in Western societies commonly begin to experiment with alcohol and/or cannabis during their adolescent years. Many experience negative consequences from the use of these substances and a minority develop pathological problems such as abuse and dependence. Previous research has identified myriad individual and environmental variables that precede and predict problematic substance use. Two such risk factors are the personality trait impulsivity and the influence of substance-using peers. This thesis aimed to study possible interactive effects of these factors on adolescent alcohol and cannabis use. A systematic review of the literature identified that a trait termed urgency, reflecting emotion-based impulsivity, showed larger associations than other impulsivity-related traits with problematic alcohol use. A study of 270 adolescent students found urgency to be significantly related to problematic alcohol and cannabis use. This study also identified a moderating effect of urgency on the relationship between perceived peer alcohol use and own problematic use. These findings were replicated in a late adolescent undergraduate sample. A three month follow-up of these participants found that urgency also predicted later problematic alcohol use. Next, an experimental study sought to identify social and emotional conditions in which impulsivity-related traits might influence alcohol use more strongly. This study found that an approach-motivated positive mood state and the presence of a friend did not influence trait effects on alcohol consumption in a beer taste test, although a main effect of sensation seeking was identified. The final study of the thesis considered how affective associative thoughts might explain links between urgency, peers, and substance use, particularly amongst adolescents. These findings help to further understanding of the role of impulsivity in adolescent substance use, and contribute to theoretical models of risk for substance use disorders.